<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
</head>
<body>
	<p id="aaa">123456</p>
	<h2 id="bbb"></h2>
	<i>5555</i>

	<script>
		document.getElementById('aaa').innerHTML="<p>修改标签</p>";
		document.getElementById('bbb').innerHTML=document.getElementById('aaa').innerHTML;

	</script>


</body>
</html>